1. Technical Field
The present invention relates generally to an apparatus to be used with semiconductor test systems, and more specifically to an apparatus for imposing a thermal environment when using a semiconductor test system.
2. Background
The advanced state of the art of electronic devices is apparent from the diversity of the functions and good performance of such devices, particularly in view of their small size. Analytical methods are usually applied to evaluate and characterize newly manufactured semiconductor wafers and devices. It is only through the use of accurate characterization and evaluation that improved devices can be successfully fabricated.
The testing of integrated circuits (IC's) during engineering development and production is performed by an IC tester such as a Hewlett Packard HP82000 tester, manufactured by Hewlett-Packard company, Palo Alto, Calif. Such board testers are widely used in the electronics industry as a tool for troubleshooting and performance evaluation and verification.
While characterizing IC chips and the like, environmental factors, such as variations in temperature, humidity, etc., can be a source of inaccuracy if not included in the test variables. One objective of environmental testing in the characterization of an IC chip is to predict the ranges in which a given device will function and to assure that design specifications are being met. Environmental or thermal testing provides a tool to aid in designing IC chips and devices with performance tolerances that prevent failure rates, due to environment-activated failure mechanisms and from exceeding acceptable limits for a particular application.
True at-speed wafer testing is a time consuming process with many hardware dependencies. Accordingly, it takes a substantial amount of time to ready a testing device, such as the Hewlett Packard HP82000 tester and it is difficult and undesirable to interrupt the tester during a procedure. Furthermore, a substantial amount of time is required to test each IC device. Therefore, the user would generally want to monitor as many parameters as possible during testing, including environmental conditions and thermal tolerances for the device under test.
This invention uses a standard tester such as the HP82000 and allows IC semiconductor chips to be tested for environmental tolerances during product characterization.